# 30 leading Public Relations and Communications Services companies in London
Tamtam tracks 57 Public Relations and Communications Services companies headquartered in London. This list ranks the 30 largest by number of employees on LinkedIn, led by PREMIER, Onclusive and Nucleus Global, an Inizio Company. Their median headcount is 239. Half of them were founded in 2001 or later.
These London-based companies specialize in public relations and communications services, ranging from large established agencies to newer firms. PREMIER focuses on entertainment, arts, and culture communications, while Onclusive offers data-driven PR insights and media monitoring. Nucleus Global specializes in scientific communications, and Grayling is a global communications agency with a wide network.
A notable pattern among these companies is their diverse specializations within the communications sector. For example, PURPLE serves the beauty, fashion, and lifestyle industries, KARLA OTTO focuses on fashion and culture, and Cavendish provides services for the built environment. All listed companies are headquartered in London.
๐ฌ๐ง London ยท 30 companies ยท Updated Nov 15, 2026
| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [PREMIER](https://www.tamtam.ai/c/premier-london) (premiercomms.com)
This company specializes in creative communications for entertainment, arts, and culture through PR, events, partnerships, social media, and experiential marketing | Public Relations and Communications Services | ๐ฌ๐ง London | 1,449 | |
| 2 | [Onclusive](https://www.tamtam.ai/c/onclusive) (onclusive.com)
Global PR and Communications partner offering data-driven insights, consultancy, workflow tools, and media monitoring to elevate performance and prove value | Public Relations and Communications Services | ๐ฌ๐ง London | 1,098 | |
| 3 | [Nucleus Global, an Inizio Company](https://www.tamtam.ai/c/nucleus-global-an-inizio-company) (nucleusglobal.com)
Innovative family-driven company specializing in scientific communications, with a team of experts in medical, digital, creative, and patient engagement for impactful outcomes | Public Relations and Communications Services | ๐ฌ๐ง London | 696 | |
| 4 | [Piaryum Communication & Media](https://www.tamtam.ai/c/piaryum-communication-and-media) (piaryum.com)
UK-based agency offers media consultancy, planning, marketing, health tourism, event management, production, content creation, and advertising services across the United Kingdom. | Public Relations and Communications Services | ๐ฌ๐ง London | 680 | 2019 |
| 5 | [Grayling](https://www.tamtam.ai/c/grayling) (grayling.com)
Global communications agency with 32 offices worldwide and affiliate network, leveraging insights, influencers, cultures, and communities to create client advantage | Public Relations and Communications Services | ๐ฌ๐ง London | 534 | |
| 6 | [PURPLE](https://www.tamtam.ai/c/purple-london) (purplepr.com)
A boutique PR agency specializing in press relations, editorial procurement, product placement, and event management for beauty, fashion, lifestyle, and entertainment industries | Public Relations and Communications Services | ๐ฌ๐ง London | 529 | 1997 |
| 7 | [KARLA OTTO](https://www.tamtam.ai/c/karla-otto) (karlaotto.com)
Full-service brand-building agency offering strategy, creative, talent, experiences, and communication services across fashion, beauty, design, lifestyle, and culture. | Public Relations and Communications Services | ๐ฌ๐ง London | 508 | 1982 |
| 8 | [Portland](https://www.tamtam.ai/c/portland) (portland-communications.com)
Portland provides strategic counsel and execution by leveraging expertise in politics, media, digital campaigns, branding, and PR to drive impactful communication | Public Relations and Communications Services | ๐ฌ๐ง London | 399 | 2001 |
| 9 | [Frank](https://www.tamtam.ai/c/frank-london) (welcometofrank.com)
This creative agency with offices in London, Manchester, and Sydney generates buzz through insight-led campaigns, focusing on great ideas to drive conversations | Public Relations and Communications Services | ๐ฌ๐ง London | 367 | 2000 |
| 10 | [Harvard](https://www.tamtam.ai/c/harvard) (harvard.co.uk)
New PR and communications powerhouse from VCCP. Integrates market leaders in consumer, corporate, technology, and financial services for commercial value. | Public Relations and Communications Services | ๐ฌ๐ง London | 342 | 2025 |
| 11 | [Communication Workers Union](https://www.tamtam.ai/c/communication-workers-union) (cwu.org)
Representing nearly 200,000 members in the UK communications industry, with expertise in engineering, technology, finance, and manual skills Join us today | Public Relations and Communications Services | ๐ฌ๐ง London | 331 | |
| 12 | [SCIRIS](https://www.tamtam.ai/c/sciris) (sciris.com)
SCIRIS is a global communications and consultancy firm, uniting diverse expertise to deliver innovative healthcare solutions inspired by science | Public Relations and Communications Services | ๐ฌ๐ง London | 311 | |
| 13 | [MHP Group](https://www.tamtam.ai/c/mhp-group) (mhpgroup.com)
An integrated communications agency specializing in applying behavioral science to solve complex challenges across various sectors and disciplines Trusted by leading businesses worldwide | Public Relations and Communications Services | ๐ฌ๐ง London | 266 | 2010 |
| 14 | [Cavendish](https://www.tamtam.ai/c/cavendish-london) (cavendishconsulting.com)
Specialist communications consultancy providing expert counsel and services for the built environment, offering public affairs, planning, PR, marketing to maximize opportunities and reduce risk | Public Relations and Communications Services | ๐ฌ๐ง London | 246 | |
| 15 | [Sutton](https://www.tamtam.ai/c/sutton) (suttoncomms.com)
International agency specializing in strategic communications, marketing, and partnerships for visual arts, performing arts, design, and cultural enterprises worldwide. | Public Relations and Communications Services | ๐ฌ๐ง London | 239 | 2006 |
| 16 | [CDR (Citigate Dewe Rogerson)](https://www.tamtam.ai/c/cdr-citigate-dewe-rogerson) (cdrconsultancy.com)
Global consultancy providing strategic communications and reputation management services, partnering with companies, organizations, and individuals for trusted advice. | Public Relations and Communications Services | ๐ฌ๐ง London | 228 | 1987 |
| 17 | [Camargue](https://www.tamtam.ai/c/camargue) (camargue.uk)
An award-winning employee-owned communications agency offering strategic advice, creative campaigns, and reputation management for businesses across various sectors | Public Relations and Communications Services | ๐ฌ๐ง London | 187 | 1987 |
| 18 | [Camron](https://www.tamtam.ai/c/camron) (camronglobal.com)
This company advocates for the impact of design in businesses, works with top designers, and extends its reach into urban planning globally | Public Relations and Communications Services | ๐ฌ๐ง London | 186 | 1989 |
| 19 | [Milltown Partners](https://www.tamtam.ai/c/milltown-partners) (milltownpartners.com)
advises influential organizations and individuals on communications and public policy challenges, shaping reputations with data-driven strategies and global expertise. | Public Relations and Communications Services | ๐ฌ๐ง London | 182 | 2013 |
| 20 | [John Doe](https://www.tamtam.ai/c/john-doe) (johndoehub.com)
A creative agency specializing in building memorable brands by sparking honest conversations and grounding campaigns in emotion and truth | Public Relations and Communications Services | ๐ฌ๐ง London | 181 | 2009 |
| 21 | [Lexington](https://www.tamtam.ai/c/lexington-london) (lexcomm.co.uk)
A leading independent strategic consultancy delivering positive change to shape the future for global businesses, organizations, and society | Public Relations and Communications Services | ๐ฌ๐ง London | 163 | 1998 |
| 22 | [Hanbury Strategy](https://www.tamtam.ai/c/hanbury-strategy) (hanburystrategy.com)
Strategic advisory firm specializing in turning insight into impact through campaigns addressing communications, public opinion, and policy challenges for global brands | Public Relations and Communications Services | ๐ฌ๐ง London | 150 | 2016 |
| 23 | [Hanover Communications](https://www.tamtam.ai/c/hanover-communications) (hanovercomms.com)
Award-winning consultancy advising on communication strategies for long-term success through insight, narrative shaping, influencer engagement, campaign activation, regulation navigation, and market access | Public Relations and Communications Services | ๐ฌ๐ง London | 146 | 1998 |
| 24 | [Bacchus Agency](https://www.tamtam.ai/c/bacchus-agency) (bacchus.agency)
Specializing in brand development, creative communications, content creation, and strategic partnerships, this agency offers a range of services for global campaigns | Public Relations and Communications Services | ๐ฌ๐ง London | 142 | 1998 |
| 25 | [Connect Group](https://www.tamtam.ai/c/connect-group) (connectpa.co.uk)
Specialists in public affairs and political strategy, delivering corporate communications and reputation management for prestigious UK organisations to achieve outstanding results. | Public Relations and Communications Services | ๐ฌ๐ง London | 133 | |
| 26 | [Roxhill Media](https://www.tamtam.ai/c/roxhill-media) (roxhillmedia.com)
Provides AI-driven media intelligence platform offering monitoring, database, analytics, bespoke analysis, and journalist events for PR professionals. | Public Relations and Communications Services | ๐ฌ๐ง London | 117 | 2013 |
| 27 | [LCA](https://www.tamtam.ai/c/lca) (thisislca.com)
A full-service PR consultancy specializing in campaigns, consultations, and content for the built environment sector, creating long-term value for clients | Public Relations and Communications Services | ๐ฌ๐ง London | 112 | 1999 |
| 28 | [PRCO Group](https://www.tamtam.ai/c/prco-group) (prco.com)
Global marketing and communications agency specializing in travel, real estate, and luxury lifestyle sectors Offering integrated solutions through strategic campaigns and media relationships | Public Relations and Communications Services | ๐ฌ๐ง London | 98 | 1987 |
| 29 | [Fight or Flight](https://www.tamtam.ai/c/fight-or-flight) (fightorflight.com)
A creative communications agency specializing in helping B2B brands stand out with unique PR, social, and branded content campaigns | Public Relations and Communications Services | ๐ฌ๐ง London | 96 | 2020 |
| 30 | [W Communications](https://www.tamtam.ai/c/w-communications) (wcommunications.co.uk)
An award-winning UK creative agency specializing in earned media, social, and digital services for global brands, innovators, and start-ups | Public Relations and Communications Services | ๐ฌ๐ง London | 86 | 2009 |
## How this list is built
Every company on this list has a Tamtam company profile. The industry is the one the company gives on LinkedIn; categories such as SaaS or fintech are classified by Tamtam's AI from the company's website and LinkedIn page; and the headquarters city must match the company's own address. Companies are ranked by the number of employees on LinkedIn, and the list is refreshed every night. Classifications can be wrong, so treat the list as a starting point rather than an official ranking. Last updated Nov 15, 2026.
## More company lists in London
- [The largest companies in London](https://www.tamtam.ai/l/largest-companies-london) (12,882)
- [Multinational companies in London](https://www.tamtam.ai/l/multinational-companies-london) (3,652)
- [Financial Services companies in London](https://www.tamtam.ai/l/financial-services-companies-london) (1,862)
- [Financial services firms in London](https://www.tamtam.ai/l/financial-services-firms-london) (1,824)
- [SaaS companies in London](https://www.tamtam.ai/l/saas-companies-london) (1,615)
- [Professional services firms in London](https://www.tamtam.ai/l/professional-services-firms-london) (1,248)
- [Software Development companies in London](https://www.tamtam.ai/l/software-development-companies-london) (1,217)
- [Retail chains in London](https://www.tamtam.ai/l/retail-chains-london) (942)
- [IT Services and IT Consulting companies in London](https://www.tamtam.ai/l/it-services-and-it-consulting-companies-london) (693)
- [Companies with a mobile app in London](https://www.tamtam.ai/l/companies-with-mobile-app-london) (667)
- [Consulting firms in London](https://www.tamtam.ai/l/consulting-firms-london) (648)
- [IT services companies in London](https://www.tamtam.ai/l/it-services-companies-london) (607)
- [Subscription businesses in London](https://www.tamtam.ai/l/subscription-businesses-london) (544)
- [Venture capital and private equity firms in London](https://www.tamtam.ai/l/vc-and-private-equity-firms-london) (539)
- [Marketing and communications agencies in London](https://www.tamtam.ai/l/marketing-agencies-london) (533)
- [Retail Apparel and Fashion companies in London](https://www.tamtam.ai/l/retail-apparel-and-fashion-companies-london) (498)
- [Advertising Services companies in London](https://www.tamtam.ai/l/advertising-services-companies-london) (480)
- [Companies with in-house R&D in London](https://www.tamtam.ai/l/r-and-d-companies-london) (477)
- [AI companies in London](https://www.tamtam.ai/l/ai-companies-london) (456)
- [Investment Management companies in London](https://www.tamtam.ai/l/investment-management-companies-london) (452)
- [Hotel and hospitality groups in London](https://www.tamtam.ai/l/hospitality-groups-london) (445)
- [Luxury brands in London](https://www.tamtam.ai/l/luxury-brands-london) (428)
- [AI-native companies in London](https://www.tamtam.ai/l/ai-native-companies-london) (407)
- [E-commerce companies in London](https://www.tamtam.ai/l/ecommerce-companies-london) (384)
## The same list elsewhere in United Kingdom
- [Public Relations and Communications Services companies in the United Kingdom](https://www.tamtam.ai/l/public-relations-and-communications-services-companies-united-kingdom) (83)
## The same list elsewhere
- [Public Relations and Communications Services companies in the world](https://www.tamtam.ai/l/public-relations-and-communications-services-companies-in-the-world) (760)
- [Public Relations and Communications Services companies in Europe](https://www.tamtam.ai/l/public-relations-and-communications-services-companies-in-europe) (564)
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Source: https://www.tamtam.ai/l/public-relations-and-communications-services-companies-london